Novel All-pass/Notch Filter Configuration with Cascadability

In this paper, a novel voltage-mode filter configuration is proposed. The proposed configuration employs two plus-type differential voltage current conveyors and two impedances. The circuit employs one grounded capacitor and two grounded resistors for realizing first order all-pass filter, and two grounded capacitors and two resistors for realizing second order all-pass/notch filters. The proposed circuits benefit from the features of high-input impedance and low-output impedance, which makes it appropriate for cascadability. In addition, a resistorless realization of first order all-pass filter is also explored. The theoretical results are confirmed with PSPICE simulations using 0.18 mu m CMOS parameters.